The present invention relates to a method and an apparatus for automatically and continuously determining and displaying the sedimentation rate of particles in suspension or composing any type of liquid but more particularly a complex biological liquid.
In medical analysis laboratories, measurement of the sedimentation rate of blood is still carried out in an entirely manual fashion.
After the sample of blood is taken, the personnel place the liquid in graduated tubes maintained in a vertical or upright position on an appropriate support.
Measurement consists in noting the variation in position of the interphase or border at regular time intervals, for example every half-an-hour or every quarter-hour. At the end of the regulation time period, total duration of the measurement, the height of drop is noted and referred to the customer sheet in the form of the ratio of the height of drop in millimeters to the time elapsed, expressed in hours.
For reasons of efficacy and profitability, in all laboratories several measurements are carried out simultaneously. It is then necessary for the person concerned with these measurements conscientiously and scrupulously to note the times and the heights of drop of the most dense material: for blood, the red corpuscles.
The great attention needed for these measurements cannot always be provided because, for reasons of efficacy, personnel cannot remain in front of graduated tubes waiting for the regulation time between two positions to be measured to elapse.
Thus, over and above the drawbacks of an entirely manual measurement, the degree of efficacy in attention involved in the personal value of the operator but also the level of work load or overload all constitute a source of error and sometimes of interpretation which will call the responsibility of the laboratory into question.